Eyeglass rim-stretching apparatus



1952 J. F. SCHWEBEL, SR

EYEGLASS RIM-'STRETCHING APPARATUS Filed Jan. 4, 1951 Suventor a w W 0 55% M6 J (Zttomeg Patented Oct. 14, 1952 UNITED STATES PATENT OFFICE 2Claims.

1 This invention relates to means for stretching the rims ofnon-metallic ophthalmic frames.

The rims of present day ophthalmic frames I are seldom round andstretching of said rims,

when necessary, cannot be efiiciently carried out unless several spacedpoints of such asymmetric rims are engaged by the stretching means.Accordingly, it is an object of this invention to provide expansiblerim-engaging means that automatically adjusts itself to the asymmetricform of a rim to more efficiently stretch said rim as said means isexpanded.

Another object of the invention is to provide novel apparatus thatembodies both rimstretching means and means for removing the rims fromthe stretching means.

The invention also has for its objects to provide such means that arepositive in operation, convenient in use, easily installed in a workingposition and easily disconnected therefrom, economical of manufacture,relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novelcombinations and arrangements of parts, which will more fully appear inthe course of the following description. However, the drawings merelyshow and the following description merely describes one embodiment ofthe present invention, which is given by way of illustration or exampleonly.

In the drawings, like reference characters designate similar parts inthe several views.

Fig. 1 is a longitudinal sectional view of rimstretching means accordingto the present invention.

Fig. 2 is a cross-sectional view thereof as taken on line 22 of Fig. 1.

Figs. 3 and 4 are fragmentary plan sectional views as taken on theplanes of lines 3-3 and 4-4, respectively.

Fig. 5 is a vertical sectional View showing rimremoving means.

As illustrated in the drawing, the invention contemplates the provisionof means In for applying heat to the rim I I of an ophthalmic frame, afrusto-conical member I2 supported in means I0, means l3 for engagingrim I I to apply the same to member I2 and thereby stretch said rim, andmeans It for effecting removal of the stretched rim from the means I3.

The means I is generally conventional and, as shown, comprises a tray orbox containing a quantity of common table salt I6. By applying heat totray I5, the salt is heated and serves as the medium for effecting safenon-vaporizing 2 transfer of heat to a non-metallic ophthalmic frameimmersed therein.

The frusto-conical member I2 is preferably made of aluminum and, whileshown is of circular cross-section, may be oval or otherwise formed. Themember I2. is proportioned so that the same will fit into the full rangeof rim sizes, smaller rims fitting nearer the smaller top of said memberand larger rims nearer the larger bottom thereof. Said member I2 is setinto tray I5 and is surrounded by salt I6. It will be understood that bypressing down on a rim placed over member I2, said rim, due to the heatexchange with the salt, will be rendered plastic and will be stretchedaccording to the diametral size of that portion'of member I2 which isengaged with the rim. As the rim stretches, the same is pressed downinto successively larger portions of member I2.

The means I3 is provided for holding the rim while the same is beingstretched and comprises the means for exerting downward pressure on therim. The means I3 comprises, generally, a mounting disc IT, a set offingers I8 carried by said disc and engageable with a rim II, and ascrew member I9 extending axially through the disc I I and serving tolimit the rim-stretching movement of the device and also as a jackingmeans to effect removal of the device and the rim from cone member I2.

The mounting disc I! is generally circular and is provided in itsperipheral face with a groove into which is fitted a circular wire 2|. Aset of radial recesses 22 is formed in the peripheral portion of thedisc, the same being loosely receptive of the upper ends of fingers l8.The wire 2|, where the same spans across said recesses, constituteshinges for said fingers. A through central and tapped hole 23 isprovided in the disc for screw member I9.

The fingers I8 are uniformly arranged and, in this case, are arranged infour groups: a group 24 of six fingers for engaging the more roundedlower portions 25 of rim II; an opposed group 26 of five fingers forengagin the flatter less rounded upper portion 21a. of said rim; and twosimilar groups 21 that separate groups 24 and 26. Figs. 1, 3 and 4 showfinger groups 21 and it will be seen from Figs. 3 and 4 and from thespaces between groups 24 and 2B in Fig. 2, that there are two fingers ineach group 21.

All of the fingers comprise elongated fiat members, of which the fingersof groups 24 and 2'6 are longer than the fingers of groups 21. Thelatter fingers serve primarily as spacers filling out the circulararrangement of fingers, said shorter fingers terminating short of wherethe nose piece 28 and temple extensions 28 are located on a rim.

Each finger 30 of groups 24 and 26, near its free end, is provided witha notch 31 formed in the inner edge thereof, the same terminating inupper and lower hooks, respectively, 32 and 33. Below thenotch, eachfinger is formed to have a sloping cam face 34.

Intermediate their ends, the fingers are connected by a circular coiledspring 35 that passes through holes 36 provided in the fingers. Spacertubes 31 are strung on said spring to space the fingers so thatnormally, they are substantially parallel under contraction by thespring.

The screw member [9 comprises a threaded stem 38 engaged in hole 23 andhaving at its upper end a manipulating knob 39.

The means I4 comprises a metal tube 40 in one end of which is providedopposed recesses 4|. Fig. shows only one of said recesses, but it willbe understood that the other is substantially opposite or rather in suchalignment that the nose piece 28 and temple extension 29, when the rimis placed on the tube '40, reside above 'said recesses.

In use, a rim II to be stretched, is strung on cone l2. With the screwmember retracted upwardly, the rim-engaging means I3 is applied over theend of the cone. Since the fingers 3B of said means are contractedinwardly by spring 35, the cam faces 34 will ride the conical face ofthe cone until said cam faces ride over the rim, being spread orexpanded to allow continued downward movement of means [3. As hooks 33slip past the rim, spring 35 will contract the fingers inwardly and therim will be engaged in notches 3|, as shown in Fig. 1. Now, while heatis applied to means In, downward pressure is slowly applied to eitherknob 39 or disc [1, so that hooks 32, which engage over the rim, mayforce the same tightly against successively larger portions of cone [2.As the heat transferred to the rim softens the same, the rim willenlarge accordingly. Since hooks 32 of the several fingers engage spacedportions of the rim, the enlargement of the latter is effectedsubstantially uniformly, thereby minimizing 'the danger of fracture ofthe rim and also undue distortion thereof.

During this rim-stretching process, the lower end of stem 38 can be setto rest against the top of cone l2 and the screw member gradually backedoff as rim expansion takes place. this manner the expansion pressure onmeans I3 is limited and controlled by said screw member.

When the rim has been suitably stretched, a quick upward pull on means13 will bring hooks 33 against the rim to dislodge the same from thecone. However, it is preferred to dislodge the rim by utilizing thescrew stem 38 as a jack by threading the same against the end of thecone to effect withdrawal of the rim by hooks 33.

It will be realized that the rim and the lower ends of fingers 30 havebeen subjected to heat and that it is inconvenient to handle the same toeffect removal of the rim from the notches 3 I. By placing the lowerends of the fingers over the means l4 and pressing downwardly, the camfaces 34 are spread, allowing the rim to fall onto the top edge of tube40. This removal of the rim can be done quickly before the samerecontract, enabling insertion of a lens into the rim while the same isin an expanded state. When the rim cools, it will contract over the lensand hold the same firmly.

While the invention that has been illustrated and described is nowregarded as the preferred embodiment, the construction is, of course,subjected to modifications without departing from the spirit and scopeof the invention. It is, therefore, not desired to restrict theinvention to the particular form of construction illustrated anddescribed, but to cover all modifications that may fall within the scopeof the appended claims.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is: I

1. An ophthalmic rim-stretching device adapted for use in cooperationwith a frusto-conical member, said device comprising a disc having athreaded aperture therein, a set of elongated fingers arranged aroundthe periphery of the disc and hinged thereto, spring means intermediatethe ends of the fingers connecting the same to contract toward eachother, a screw stem in said aperture and extending generally centrallyamong the fingers, an end of said stem being adapted to engage thesmaller end of said frusto-conical member and to be turned relative tosaid disc and fingers to move said disc and fingers longitudinally ofthe stem and of the frusto-conical member, a cam face provided on theinwardly-facing edge of a majority of said fingers to cam over anophthalmic rim strung on the frusto-conical member, and a downwardlydirected hook provided on said inwardly-facing edge of each of saidfingers and above each said surface to hook onto said rim to force saidrim in a direction toward the larger diameter of said frusto-conicalmember and to stretch said rim accordingly as the disc and fingers aremoved in said direction.

2. A rim-stretching device according to claim 1: the fingers providedwith the cams and hooks being divided into two substantially opposedgroups to engage upper and lower portions of the rim, the remainingfingers being shorter than the fingers having the hooks to be spacedfrom the rim during stretching thereof, and all of the fingers beingarranged in substantially uniform spacing.

JOHN F. SCHWEBEL, SR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 491,853 Noe Feb. 14, 18931,572,776 De Nome Feb. 9, 1926 1,632,266 Baker June 14, 1927 1,685,167Ljunglof Sept. 25, 1928 1,764,116 Noble June 17, 1930

